Question

The multiplicative inverse of $9^{-100}$ is

• A. $\frac{100}{9}$
• B. $\frac{9}{100}$
• C. $9^{100}$
• D. ${100}^9$

Answer 1

The correct option is C $9^{100}$

If $b$ is multiplicative inverse of $a$ , then we have $ab=1$

Put $a=9^{-100}$ , we get $b\times 9^{-100}=1$

$\Rightarrow b=9^{100}$

Therefore the multiplicative inverse of $9^{-100}$ is $9^{100}$

So the correct option is $C$